Astros pitching prospect out at least another month

CINCINNATI — The news on Astros Class AA reliever Chia-Jen Lo could have been worse, but he will miss significantly more time an elbow injury. Lo has already been out of action since April 30.

Lo was examined this week by Astros medical personnel, and it was revealed that the righthander has a partial tear of his ulnar collateral ligament. He will miss another 4-6 weeks, but he will not require surgery, assistant general manager Ricky Bennett said.

The Taiwanese 24-year-old was generally regarded as the Astros’ top relief pitching prospect heading into the 2010 season. He was one of two young prospects — Jason Castro being the other — given non-roster invitations to spring training at the beginning of the year.

Lo was 0-1 with a 1.80 ERA in his first seven games with Corpus Christi before the injury.